Effect of Pre-storage Heating of Broiler Breeder Eggs, Stored for Long Periods, on Hatchability and Chick Quality

This study was undertaken to determine if pre-storage heating of broiler breeder eggs, stored for long periods, would improve the hatchability and chick quality. A total of 2400 broiler breeder eggs were obtained from a 46 weeks old commercial flock. Eggs were distributed in a 3 x 4 factorial design, with three pre-storage heating durations (0, 6, and 9 hours at 37.5° C and 56% RH) and four storage periods (4, 7, 10 and 14 days at 18° C and 75% RH). This adds up to twelve treatments with 20 replicates, of 10 eggs each. After storage, eggs were simultaneously incubated under the usual incubation conditions. Eggs were weighed before heating, after storage and before transfer to the hatcher, to determine the weight loss. Fertility and hatchability of both fertile and total eggs were determined. Embryo mortality was determined in non-hatched eggs. All hatched chicks were weighed and examined to score them for quality. The results indicated that long egg storage period resulted in a significant increase in egg weight loss during storage and after 18 days of incubation, and total egg weight loss. The longer the pre-storage heating duration was significantly increased the egg weight loss percentage during storage. Hatchability and chick quality results of eggs stored from 7 to14 days were significantly less than eggs stored for 4 days. The 6 hours pre-storage heating treatment, significantly increased the hatchability and chick quality of eggs as compared to the non-heated or 9 hours heated eggs. There were significant pre-storage heating × egg storage length interactions for egg weight loss, hatchability of total and fertile eggs, embryonic mortality and chick quality. When eggs were stored for more than seven days, pre-storage heating eggs for six hours significantly improved the hatchability and chick quality results, as compared to non-heated or heated for 9 hours eggs. In conclusion, pre-storage heating of commercial broiler breeder eggs for six hours at 37.5° C and 56% RH could be used by the poultry industry as a method to improve hatchability and chick quality of eggs stored for longer periods than 7 days.